Cable terminal device for transmitting electrical drive power

ABSTRACT

A terminal device has a housing ( 1 ) of insulating material, the housing surrounding a portion of the cable end in the manner of a sleeve and having a flange ( 21 ) directed towards the terminal receptacle. There is additionally provided an inner shield sleeve ( 8 ) of conductive material arranged in the housing ( 1 ) and surrounding the cable ( 20 ), which sleeve is connected conductively to the shield ( 18 ) and which has a flanged contact zone ( 22 ) directed towards the terminal receptacle. Fastening means, preferably screws ( 6 ), are used simultaneously to press the housing ( 1 ) and the contact zone ( 22 ), resting on the housing ( 1 ), of the inner shield sleeve ( 8 ) axially against a shield housing ( 2 ) of the terminal receptacle.

The invention relates to a terminal device for transmitting electricaldrive power for a motor vehicle between a terminal receptacle and ashielded cable, and mores particularly to an electrical connectionarrangement having at least one such terminal device.

For the purposes of the present patent application, an electricalterminal device is an electrical component for firm or permanentconnection to a cable and configured to releasably connect with a matingcomponent. The mating component of the terminal device is called theterminal receptacle and the mating component of the terminal receptacleis called the terminal device.

In electrical engineering and electronics, a large number of terminaldevices and associated mating components, in particular a large numberof very different plug connectors and plug receptacles are available.These serve to transmit electrical power and/or electrical signals withthe widest possible range of voltages, currents, frequencies and datarates. To prevent the emission or coupling-in of electromagneticinterference, the complementary terminals may be provided with single ormultiple shielding in accordance with the cables or other transmissionelements connected therewith. To protect against damp, dusty, orchemically aggressive environments, terminal devices and terminalreceptacles comprise a very wide range of sealing elements. Screwfittings or latch fittings may serve to prevent separation of terminaldevices and terminal receptacles. The actual current-carryingconnections may be produced, for example, by a plug-in connection or byscrewing a cable lug crimped onto the cable together with a screwableterminal or contact provided in the terminal receptacle. Due to theextremely wide range of applications and conditions of use, a widevariety of optimized complementary terminal elements are available.

A relatively new field of use for terminal devices and terminalreceptacles is the transmission of drive power in an electrically drivenmotor vehicle. This drive power is transmitted between an energy storagemeans, for example a storage battery, a fuel cell, a generator, or otherenergy source, a power converter and one or more drive motors in onedirection or alternating in both directions. In particular, between thepower converter and the drive motor(s), the drive power may betransmitted in pulse width-modulated manner and thus with a high A.C.component. Cables or leads with shielding are used to prevent theemission of electromagnetic interference signals.

Motor vehicles with an electromotive drive existed until recently onlyin the form of prototypes or short run models. For this reason, theterminal devices and terminal receptacles which have been used in thepower transmission area are those which are readily available but aredistinguished for the most part by a robust but also very complexstructure. These terminal devices and terminal receptacles are thereforecomplex and expensive to produce and assemble.

With electrically driven motor vehicles moving into the realms of seriesand mass production, the demands placed on the terminals in the powertransmission area are also changing. They not only have to be robust andensure long-term, malfunction-free functioning over the entire life ofthe motor vehicle, but also have to be simple and cheap to produce andassemble. One of these new demands is the desire to avoid the very highplug-in forces which arise with the plug-in connectors used hitherto dueto the large lead cross-sections and the associated contact sizes. Theseassembly forces cannot be sufficiently reduced by assembly aids such aslevers. In addition, assembly aids require a very large structuralspace.

An object of the present invention is to provide a completely sealed(shield and conductor) terminal device for a shielded cable, whichallows simple, cheap production and reliable, low-force assembly onconnection with a terminal receptacle.

This object is achieved with a terminal device according to claim 1 anda connection arrangement according to claim 10 containing such aterminal device.

Advantageous further developments of the present invention are definedin the dependent claims.

The present invention is based on the concept of using a housing ofinsulating material, which surrounds a portion of the cable end in themanner of a sleeve and which comprises a flange directed towards theterminal receptacle, simultaneously for securing against separation ofterminal device and terminal receptacle and for reliable shieldcontinuity. To this end, an inner shield sleeve and a fastening meansare provided. The inner shield sleeve is constructed of conductivematerial arranged in the housing and surrounding the cable, which sleeveis connected conductively to the shield and which comprises a flangedcontact zone directed towards the terminal receptacle. The fasteningmeans enables the housing and the contact zone of the inner shieldsleeve resting on the housing to be simultaneously pressed axiallyagainst a conductive shield housing of the terminal receptacle. Thisconstruction results in a shielded terminal device for high voltages andcurrents, which may advantageously be used in hybrid and fuel cellvehicles. The terminal device according to the invention may be pluggedor screwed into the terminal receptacle for current-carrying connectionand is distinguished by low plug-in forces, a small structural space,and the possibility a single pole or multipole configuration.

An outer shield sleeve surrounding the cable may be provided to improvethe contact stability of the shield connection, said outer shield sleevebeing arranged in the housing and pushed onto the cable-side end zone ofthe inner shield sleeve, the (exposed) shield of the cable being fixedby clamping between the inner and outer shield sleeves. In an embodimentwhich is regarded as particularly advantageous, the outer shield sleevetakes the form, on the cable side, of insulation crimping for the cableand, in the area of clamping fixing of the shield of the cable, ofshield crimping. In this way, strain relief of the outer sheath of thecable is combined with shield crimping. Furthermore, a projection may beincorporated into the shield crimping for making possible orientedpreassembly of the parts relative to one another.

The terminal device according to the invention makes possible the simpleincorporation of a highly effective sealing arrangement, the particularadvantage of which is that the seals, consisting for example ofnon-conductive silicone (or another non-conductive sealing material),may be fitted in protected manner in the housing and therefore cannot bedamaged.

This sealing arrangement comprises, on the cable side, a seal and acovering cap which surround the cable, in each case, in the manner ofsleeves, the seal being introduced, in particular press-fitted, into thecable-side end of the housing and the covering cap surrounding thecable-side end of the housing provided with the seal in the manner of acap and being capable of being latched to the housing. On the oppositeside of the terminal device, sealing may be achieved by providing asecond sleeve-shaped sealing means which is screwed onto a shoulder ofthe housing formed in the area of the flange in such a way that it restssealingly between the shoulder and a sealing face formed on the terminalreceptacle upon fastening the terminal device to the terminalreceptacle.

To improve shield continuity contact stability with regard to the shieldhousing, it is advantageous for the contact zone of the inner shieldsleeve to comprise contact points and/or disc-shaped or arm-shapedcontact means. Due to the terminal device structure selected accordingto the invention, relatively large design latitude is thus possible withregard to shield continuity.

In an exemplary embodiment, the fastening means provided for mechanicalconnection of the terminal device and the terminal receptacle comprisesat least one fastening screw arranged axially in the area of the housingflange. Alternatively, at least one axially arranged snap-action hookmay be provided as a fastening means in the area of the housing flange.

Since the insulating housing of the terminal device according to theinvention is of sleeve-shaped construction, a cable lug crimped onto thecable may be provided to simply produce the current-carrying connection,where the cable lug comprises a terminal part directed towards theterminal receptacle and the terminal part is capable of being screwedtogether with the current-carrying part of the terminal receptacle.

The connection arrangement according to the invention for producingreleasable electrical connections between at least one cable and atleast one terminal receptacle comprises one terminal device of theabove-described type designed for modular side-by-side arrangement foreach cable. In this respect, it is advantageous to construct theterminal receptacles associated with the terminal devices with a commonshield housing, in which the individual current-carrying parts arearranged next to one another and against which the terminal devicehousings, which are optionally resting against one another in modularmanner, may be jointly pressed.

Exemplary embodiments of the present invention are explained below withreference to the drawings, in which:

FIG. 1 is a schematic plan view of an electrical connection arrangement;

FIG. 2 is a schematic sectional representation of the connectionarrangement;

FIG. 3 is a further schematic sectional representation of the connectionarrangement (on an enlarged scale);

FIG. 4 is a view of the connection arrangement in partially explodedrepresentation.

FIG. 1 is a schematic plan view of a connection arrangement forconnecting two cables 20 to two conductor bars 12 by means of twoterminal devices (terminals) according to the invention. The terminaldevices are of modular construction at least regarding their housing 1and, in particular, regarding the box-shaped flange 21, such that theymay be arranged side-by-side, as illustrated. The terminal receptaclestake the form, substantially, of the conductor bars 12, which areaccommodated in a common shield housing 2 of conductive material. Eachterminal device is attached to the shield housing 2, for example, by atleast one screw 6, in the axial direction predetermined by the cable 20or the associated housing 1, the housing 1 being pressed againstconductive contact surfaces of the shield housing 2 on the shieldhousing side, i.e. in the area of the flange 21. The terminal deviceadditionally comprises a sleeve-shaped sealing means 3, which is formedin the area of the flange 21 and screwed onto a shoulder of the housing1 in such a way that, upon fastening the terminal device to the terminalreceptacle, the sealing means 3 rests sealingly between the shoulder anda sealing face formed on the terminal receptacle.

In the sectional representation according to FIG. 2, it is clear, firstof all, that the cable 20 comprises the inner conductor 16, the innerinsulation 17, the shield (shielding braid) 18, and the outer insulation19. The shield 18 is clamped firm between inner shield sleeve 8 andouter shield sleeve 7, as also shown in the illustration according toFIG. 3. The outer shield sleeve 7 may take the form, on the cable side,of strain-relieving insulation crimping for the cable 20 and at the sametime, in the area where the shield 18 of the cable 20 is clamped firm,of shield crimping.

The inner shield sleeve 8 has the function of contacting the shield 18with the conductive shield housing 2. As is clear, in particular in theenlarged representation according to FIG. 3, the inner shield sleeve 8,which is optionally repeatedly offset as illustrated, rests with itsflanged contact zone 22 on the non-conductive housing 1.

The contact zone 22 of the inner shield sleeve 8 may comprisecircumferential contact points, for example, in order to ensure reliablecontacting with the associated contact surface 23 of the shield housing2. In another possible construction of the contact zone 22, the lattertakes the form, for example, of a fan-type disc or a corrugated disc orhas contact arms, wherein said elements may in each case be constructedwith or without contact points.

One or more fastening screws 6 are used to press the housing 1 and thecontact zone 22 of the inner shield sleeve 8 against the conductiveshield housing 2, so ensuring an elevated contact pressure and highvibration resistance. If requirements are not so stringent, the screws 6may be replaced by one or more snap-action hooks (not shown), which goeshand-in-hand, of course, with significantly greater ease of assembly.When the housings 1 are arranged next to one another, they rest againstone another in the area of the flange 21. The housing 1 and the shieldhousing 2 are advantageously in each case so designed that the housing 1can only be assembled in one position. In addition, both housings 1 and2 may comprise coding. Not least, it is advantageous that the flange(terminal) 21 does not itself have to have a conductive coating, despitebeing functionally incorporated into the shield connection.

The cable lug 9 crimped onto the inner conductor 16, as shown in FIGS. 2and 3, comprises an elongate hole in the screw area 10 for example, forcompensating axial tolerances. (Instead of an elongate hole, a largeropening may also be provided.) On assembly, the cable lug is introduced9 into the shield housing 2, wherein it may be positioned relative tothe conductor bar 12 via the insulation 11 serving as an assembly aid.At the same time, the insulation 11 serves as a torque bracket andpositioning means for the conductor bar 12. In the case of readilyaccessible shield housings 2, such a positioning aid is not necessary,and orientation may instead be undertaken simply by hand. The assemblyaccess cover 14 with the cover seal 15 ensures access to the screwconnection 13. In the case of readily accessible screw connections 13,the assembly access cover 14 may be dispensed with. The cable lug 9 mayalso be connected to the inner conductor 16 other than by crimping, or acable lug 9 may be wholly omitted, for instance by making the innerconductor 16 screwable by compacting welding with regard to therespective mating terminal component of the terminal receptacle.Moreover, FIG. 3 shows an interrupt device 25 for safety shutdownthrough interruption of the signal circuit, which may be implemented inthe context of the terminal device according to the invention.

FIG. 4 shows a perspective view of a connection arrangement, in whichthe inner shield sleeve 8, the outer shield sleeve 7, the seal 4,press-fittable into the cable-side end of the housing 1 and providedwith sealing lips for example, and the covering cap 5 with latchingclosure 24 are shown in exploded representation to make them clearer tounderstand. Equally possible are embodiments (not shown) in which theshield housing 2 is reduced substantially to the end plate directedtowards the flanges 21 of the housing 1, such that the connectionarrangement may be incorporated virtually directly, for example into amotor housing. In this case, the length of the connection arrangement isonly approximately 60 mm, whilst it is approximately twice that with afull shield housing 2. The contact spacing of the current-carryingconductors 9 or 12 amounts, in the exemplary embodiment shown, toapproximately 51 mm.

1-12. (canceled)
 13. A cable terminal device comprising: a housing ofinsulating material, which surrounds a portion of a cable end in theform of a sleeve and which comprises a flange directed towards aterminal receptacle, an inner shield sleeve of conductive materialarranged in the housing and surrounding the cable, the inner shieldsleeve being connected conductively to the shield and having a flangedcontact zone directed towards the terminal receptacle, an outer shieldsleeve surrounding the cable, the outer shield sleeve being arranged inthe housing and being pushed onto a cable-side end zone of the innershield sleeve, the shield of the cable being fixed by clamping betweenthe inner and outer shield sleeves fasteners, by which the housing andthe contact zone of the inner shield sleeve, resting on the housing, maysimultaneously be pressed axially against a conductive shield housing ofthe terminal receptacle.
 14. A cable terminal device according to claim13, wherein the outer shield sleeve takes the form, on the cable side,of insulation crimping for the cable and, in the area where the shieldof the cable is clamped firm, of shield crimping.
 15. A cable terminaldevice according claim 13, wherein a sealing arrangement is provided,which comprises a seal and a covering cap, which surround the cable theseal being press-fitted into the cable-side end of the housing and thecovering cap surrounding the cable-side end of the housing provided withthe seal capable of being latched to the housing.
 16. A cable terminaldevice according to claim 13, wherein a second sleeve-shaped seal isprovided, which is screwed in such a way onto a shoulder of the housingformed in the area of the flange that it rests sealingly between theshoulder and a sealing face formed on the terminal receptacle onfastening of the terminal device to the terminal receptacle.
 17. A cableterminal device according to claim 13, wherein the contact zone of theinner shield sleeve comprises contact points and/or disc- or arm-shapedcontact means.
 18. A cable terminal device according to claim 13,wherein at least one fastening screw arranged axially in the area of theflange of the housing is provided as fastening means.
 19. A cableterminal device according to claim 13, wherein at least one snap-actionhook arranged axially in the area of the flange of the housing isprovided as fastening means.
 20. A cable terminal device according toclaim 13, wherein a cable lug crimped onto the cable comprises aterminal part directed towards the terminal receptacle, the terminalpart being capable of being screwed together with the current-carryingpart of the terminal receptacle.